Materials Science

What is a 'Medical-Grade' Polymer?

The Association of German Engineers (VDI) has embarked on defining a standard for ‘medical grade polymers’, with the first draft being presented at the VDI congress in April 2018. Here, Siobhan Bastiansen, Market Manager Medical Plastics at VELOX, explains why a binding definition would benefit both material suppliers and device manufacturers.

Polymers have been used in the healthcare and medical industry for decades. However, when it comes to choosing the right polymer for a specific medical or pharmaceutical application, things can get complicated. Despite strict international and national regulations for medical polymers, as well as demanding requirements, there has been no universally accepted definition of ‘medical-grade’ polymers so far.

Complex policies and disclaimers

After several high-profile and costly litigations in the '90s, companies that actively market their polymers for medical applications typically have policies regarding restricted or permitted applications like ‘skin contact only’ or ‘max. 24 hours inside the body’. These restrictions may not be related to the expected performance of the polymer in the target application, but rather reflect the corporate environment and legal department’s decisions. They can have much more to do with perceived risk exposure to litigation down the line. Very few polymer suppliers take the braver route of having a disclaimer reminding that the choice of polymer is up to the device manufacturer. For medical device manufacturers, it can be challenging to keep track of complex policies and disclaimers.

While polymer producers have determined their own individual set of characteristics to define a medical grade, medical device manufacturers have been theoretically free to choose any polymer, as long as they followed existing regulations, while carrying the risks involved with product liability. Many device manufacturers have relied on compliance with applicable standards such as USP Class VI and ISO 10993, with regard to biocompatibility when choosing the material for their application.

The new European Union Medical Device Regulation 2017/745 (MDR), which will be mandatory from 26th May 2020, places a strong emphasis on risk management and safety. It comprises new classification rules as well as extra surveillance and safety reports, and also reinforces the position of notified bodies, demanding that they “carry out unannounced on-site audits and to conduct physical or laboratory tests on devices to ensure continuous compliance by manufacturers after receipt of the original certification”.

These requirements will make market entry for new products extremely difficult and expensive. Yet, when it comes to an industry-wide, standard definition for medical-grade polymer, the new MDR remains silent.

First step to a binding definition

However, things are changing in Germany. The Association of German Engineers, VDI, has implemented a committee for defining a standard for medical-grade polymers. A standard definition would bring more reliability, stability and long-term commitment for polymer manufacturers and medical device producers alike. A first draft was presented at the VDI symposium Plastics in Medical Technology, which took place in April 2018 in Friedrichshafen. The final guideline will be available at the end of 2018.

Change management and long-term commitment

In the meantime, polymer suppliers that develop and provide specialized polymers for medical applications have discovered a significant gap in this complicated situation to add value for the manufacturers. Suppliers like Repsol or LubrizolLifeSciences, that have been cooperating with VELOX for many years, have put transparent mechanisms into place to ease the process of change control and to secure a long-term supply.

The typical dynamic in chemical plants producing hundreds of thousands of tonnes of resins, for example, is to strive for continuous improvement in efficiencies, quality, innovation and economics. By implication, things are always changing – new grades bring advantages and old grades become obsolete – which is great for our industrial customers but can be a challenge for medical customers. The challenge in setting up a portfolio of products for use in the medical device industry is in understanding the needs of medical and pharma companies and to put the necessary product stewardship in place across all the stakeholders within the organization. This means production, purchasing, logistics, R&D as well as sales and marketing.

In other words, knowing your supplier and being sure that they know you and your application is the ideal scenario. They can give the right support, advise you and be there for the long term, which is crucial for success across the lifetime of the product. This is even more true within the context of the new MDR.